Have you heard the legend of lemmings committing suicide by collectively jumping into the sea?
This is a relatively widely circulated animal phenomenon, telling the story of a rodent lemming, jumping from a cliff by the sea in droves and committing suicide en masse.
Regarding the causes of collective suicide, there are various, the most widely spread and the most magical is: the number of lemmings has grown too fast, in order to achieve sustainable growth, driven by instinct, lemmings collectively jump into the sea to commit suicide, which is a "brave jump".
Is it true that lemmings commit suicide by jumping into the sea?
Obviously, this is just a myth, a product of people's imagination.
Lemmings have a strong reproductive ability, a pair of lemmings in a summer can give birth to 3-5 nests, each litter of 8-10 lemmings, so every three or five years the number will rise sharply, due to continuous saturation, the pressure of the growing environment increases, lemmings have to migrate to other places to live, jump into the sea, for them, just jump into the water, swim to the other shore only, and they themselves will swim, so jumping into the sea is just for migration, and suicide has nothing to do with it.
The "Year of the Lemmingham" begins repeatedly, once every three or five years
Although the "suicide" incident is a beautiful legend, one thing is certain, the peak of lemmings occurs every three to five years.
In the so-called Lemming Year, hundreds of lemmings can be seen in the mountains or in the water, which also benefits many lemmings-feeding animals, such as many predators, birds of prey and owls.
In the Year of the Lemming, the food of these animals is sufficient, so the number of these animals will also increase, and once the number of natural enemies increases, the lemmings will decline, and the ecology will be circulated.
In addition to known predators, another aquatic animal also includes lemmings in the menu
A professor at the Norwegian University of Life Sciences said another aquatic animal had been found, involved in the ecological cycle of lemmings. A trout from an alpine lake may eat a lot of lemmings.
For years, researchers have been studying salmon and trout in an alpine lake in Norway.
In the data-collecting study in late August and early September 2018, the researchers and his students fished a total of 27 trout fish, 36 to 48 centimeters long.
Among them, 5 trout have a lemming in their stomachs, and 1 1.2 kg trout has 1 lemming and 2 voles in their stomachs, which means that 22% of trout have eaten lemmings.
We all know that trout generally feed on insects, small crustaceans and small fish, and this surprising discovery also shows that the diet of trout is diverse, at least small rodents such as lemmings and voles are also its dishes.
Does trout contribute significantly to the lemming ecological cycle? Can it eat a lot of lemmings?
The researchers believe that in the lake studied, trout is not caught in large quantities, and the number is very impressive. It is estimated that a large number of people are more than 10 years old, and some are even more than 20 years old, and their body size is relatively large, and the largest may have exceeded 50 centimeters.
According to official statistics, in 2017, the number of trout in the lake exceeding 36 centimeters was around 1200.
At the beginning of September 2018, at a rate of 22%, about 300 large trout in the lake enjoyed a feast, and lemmings became the food source of nutrition for most trout, starting in early summer and eating until autumn.
And there are many more lakes like this, so trout participate in the ecological cycle of lemmings in unexpected forms.
Similarly, like other predators, the number and size of trout varies with lemmings.